Mysterious Eye: The Marvellous Machinery That Controls Your Sight

When a cataract develops, the lens of the affected eye becomes cloudy due to changes to the structure of a protein in the lens. As this protein clumps together, it prevents light from travelling past the lens to the retina. This can cause complete loss of vision if the entire lens is allowed to become opaque. Here's an overview of the three main types of cataracts and the treatment process:

Nuclear

This type of cataract is age-related and occurs when the natural process of aging causes changes to the protein in the centre of the lens. Due to the protein clustering in the centre, the way your eye focuses can change, and this causes a temporary improvement in your sight when looking at objects at close range. Nuclear cataracts tend to develop slowly over several years and usually affect both eyes.  

Cortical

This type of cataract starts to form on the outer edge of your lens and is typically found in diabetics with poorly-controlled blood sugar levels. When your blood sugar levels are elevated, the cells in your lens can be damaged by a type of sugar alcohol, and this damage is not reversed when you bring your blood sugar levels back within the normal range. Cortical cataracts affect your ability to see both near and distant objects.

Subcapsular

This type of cataract can occur as a side-effect of taking prescription corticosteroids for a prolonged period of time. Corticosteroids are commonly used as a long-term treatment for those with an inflammatory autoimmune disease, such as rheumatoid arthritis and Crohn's disease. A subcapsular cataract affects the rear of the lens and can cause sensitivity to both artificial and natural light and blurred vision.

Treatment

The only treatment option for a cataract is surgical removal, and as cataracts worsen if left untreated, it's best to have them removed as soon as possible to prevent unnecessary discomfort. Cataract surgery is carried out under local anaesthetic as a day case procedure and involves removing the clouded lens and replacing it with an artificial lens. The damaged lens is broken down with ultrasonic waves, and the tiny pieces of the lens are suctioned away. The artificial lens can be made with a focusing capability that would, in some circumstances, allow those who wear glasses to see fine without them.

A cataract can be present and affect your eye health before you notice changes to your vision or develop a noticeable opaqueness of the lens, so ensure you have regular eye exams and see your optometrist regularly.